Sweeping outdoor areas such as lawns, pedestrian streets, parking places and the like of leaves, grass clippings and other debris is typically accomplished using hand tools such as rakes and brooms. Although effective, hand tools are slow and laborious, a significant drawback when maintaining large areas.
An alternative device for grounds keeping is a “leaf blower,” which uses an internal combustion engine or an electric motor to operate a fan, which generates an air stream expelled from a tube. The user aims the tube at the debris, using the air stream to gather or disperse the debris. A shortcoming of leaf blowers is their tendency to hurl the debris at high velocity, which often leads to damage to nearby objects such as automobiles. In addition, it can be laborious and time-consuming to urge debris around various objects such as shrubbery and automobiles using a leaf blower.
Some leaf blowers are convertible for use as either a blower or a vacuum by attaching an elongated tube to either an air inlet or an air outlet of the fan housing. In a blower mode, a concentrator tube concentrates air expelled through the air outlet to create a highly-directed stream of high velocity air at the end of the tube. A cover is placed over the air inlet to prevent accidental ingestion of objects while permitting a free flow of air into the air inlet. In a vacuum mode, the concentrator tube is removed from the air outlet. A vacuum tube, typically having a larger diameter than the concentrator tube, is attached to the air inlet after the cover is removed. Air drawn through an opening in the end of the vacuum tube tends to entrain objects loose in the vicinity of the end of the tube. The objects are carried by the flow into the fan and then discharged into a porous sack hung around the air outlet to collect debris. A particular problem with these devices is that of gathering solids such as animal waste. These solids are typically too heavy to be drawn into the concentrator tube or, if drawn in, may become lodged in the tube. In addition, collecting animal wastes with such devices can be unpleasant due to odors from collected wastes emanating from the porous sack.